Digital beamforming for cellular technology applications

ABSTRACT

Embodiments of the present disclosure relate to cellular technology applications of beamforming performed in the digital domain. In one aspect, an RF system for performing digital beamforming on a per-carrier basis is disclosed, where different phase and/or amplitude adjustments are applied to signals of different frequency ranges (i.e., to different carrier signals). In another aspect, an RF system for performing digital beamforming on a per-antenna basis is disclosed, where different phase and/or amplitude adjustments are applied to signals transmitted from or received by different antennas. In some embodiments, an RF system may be configured to implement both digital beamforming on a per-carrier basis and digital beamforming on a per-antenna basis. The RF systems disclosed herein allow implementing programmable beamforming in the digital domain in a manner that is significantly less complex than conventional implementations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation and claims the benefit of priorityunder 35 U.S.C. 120 of U.S. Non-Provisional patent application Ser. No.16/902,769, filed 16 Jun. 2020, entitled “DIGITAL BEAM FORMING FORCELLULAR TECHNOLOGY APPLICATIONS,” the disclosure of which is consideredpart of and is incorporated hereby by reference in its entirety.

TECHNICAL FIELD OF THE DISCLOSURE

The present disclosure generally relates to radio frequency (RF) systemsand, more particularly, to systems and methods for realizing digitalbeamforming in cellular applications.

BACKGROUND

Radio systems are systems that transmit and receive signals in the formof electromagnetic waves in the RF range of approximately 3 kilohertz(kHz) to 300 gigahertz (GHz). In context of RF systems, an antenna is adevice that serves as an interface between radio waves propagatingwirelessly through space and electric currents moving in metalconductors used in a transmitter or a receiver. During transmission, aradio transmitter supplies an electric current to the antenna'sterminals, and the antenna radiates the energy from the current as radiowaves. During reception, an antenna intercepts some of the power of aradio wave in order to produce an electric current at its terminals,which current is subsequently applied to a receiver to be amplified.Antennas are essential components of all radio equipment, and are usedin cell phones, satellite communications, radio broadcasting, broadcasttelevision, two-way radio, communications receivers, radar, and otherdevices.

A single antenna will typically broadcast a radiation pattern thatradiates equally in all directions in a spherical wavefront. Phasedantenna arrays generally refer to a collection of antennas (alsoreferred to as “antenna elements”) that are used to focuselectromagnetic energy in a particular direction, thereby creating amain beam, a process commonly referred to as “beamforming.” Phasedantenna arrays offer numerous advantages over single antenna systems,such as high gain, ability to perform directional steering, andsimultaneous communication. Therefore, phased antenna arrays are beingused more frequently in a myriad of different applications, such asairplane, automotive and industrial radar, cellular technology, Wi-Fiand other short-range communication technologies, and militaryapplications.

Implementing beamforming in cellular technology applications presentsunique challenges not found in other applications. One reason for thatis the requirement for cellular devices to transmit and receivedifferent carrier signals (i.e., signals in different frequency bands).As a result, designing an optimal RF transceiver (i.e., an RF devicethat can both send and receive RF signals having information encodedtherein), capable of performing desired beamforming for cellulartechnology applications is far from trivial. A variety of factors canaffect the cost, quality and robustness of a beamforming arrangementemployed in such a transceiver. Physical limitations such asspace/surface area, as well as limitations that may be imposed byregulations, can pose further constraints to the requirements orspecifications of beamforming in cellular technology applications, and,thus, trade-off and ingenuity must be exercised.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present disclosure andfeatures and advantages thereof, reference is made to the followingdescription, taken in conjunction with the accompanying figures, whereinlike reference numerals represent like parts, in which:

FIG. 1 illustrates an example cellular wireless communication system,according to some embodiments of the present disclosure;

FIG. 2 provides a block diagram illustrating an example RF systemconfigured to implement per-carrier and/or per-antenna digitalbeamforming for cellular wireless communications, according to someembodiments of the present disclosure;

FIG. 3 provides a block diagram illustrating an example antenna arraythat may be used in the RF system shown in FIG. 2, according to someembodiments of the present disclosure;

FIG. 4 provides a block diagram illustrating an example RF systemconfigured to implement per-antenna digital beamforming for cellularwireless communications, according to some embodiments of the presentdisclosure;

FIG. 5 provides a block diagram illustrating an example RF systemconfigured to implement per-carrier digital beamforming, e.g., on aper-antenna basis, for cellular wireless communications, according tosome embodiments of the present disclosure;

FIG. 6 provides a block diagram illustrating per-carrier beamforming ina transmit path of a K-channel transceiver cell of an RF system,according to some embodiments of the present disclosure; and

FIG. 7 provides a block diagram illustrating an example data processingsystem that may be configured to implement, or control implementationof, at least portions of digital beamforming as described herein,according to some embodiments of the present disclosure.

DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE DISCLOSURE

Overview

The systems, methods, and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for allof the desirable attributes disclosed herein. Details of one or moreimplementations of the subject matter described in the presentdisclosure are set forth in the description below and the accompanyingdrawings.

For purposes of illustrating RF systems (e.g., RF transceivers)configured to implement digital beamforming for cellular technologyapplications, proposed herein, it might be useful to first understandphenomena that may come into play in such systems. The followingfoundational information may be viewed as a basis from which the presentdisclosure may be properly explained. Such information is offered forpurposes of explanation only and, accordingly, should not be construedin any way to limit the broad scope of the present disclosure and itspotential applications.

As described above, phased antenna arrays generally refer to acollection of antennas that are used to focus RF energy in a particulardirection, thus creating a main beam. In particular, the individualantennas of a phased antenna array may radiate electromagnetic waves ina spherical pattern, but, collectively, a plurality of such antennas maybe configured to generate a wavefront in a particular direction throughconstructive and destructive interference between the waves of the same,or substantially the same, frequency emitted by different antennas.Beamforming involves adjusting phases and/or amplitudes of the signalstransmitted by different antennas (the terms “waves” and “signals” maybe used interchangeably herein). The phase of the signals transmitted bythe antennas of a phased antenna array affects whether the signalsinterfere constructively or destructively, thus allowing the antennasystem to steer the wavefront in different directions. The radiationpatterns of the antennas may interfere constructively in a targetdirection, creating a wavefront in that direction (i.e., the main beam).A phased antenna array can realize increased gain and improve signal tointerference plus noise ratio in the direction of the main beam.Furthermore, the radiation patterns of the antennas may interferedestructively in directions other than the direction of the main beamand can reduce gain in those directions (the terms “gain” and“amplitude” may also be used interchangeably herein). The amplitude ofthe signals transmitted by the individual antennas of a phased antennaarray affects side lobe levels, where the side lobes are lobes of theradiation patterns that are not in the direction of the main beam (ormain lobe). It is generally preferable to reduce side lobe levels suchthat the antenna system can focus the cumulative radiation pattern tothe target direction.

As the foregoing illustrates, the accuracy of the control in-phase shiftand amplitude (or gain) for the collection of antennas is important tothe implementation of phased antenna arrays.

Controlling phase and amplitude of signals used for beamforming incellular technology applications presents challenges that are not foundin other beamforming applications. Cellular technology is constantlyevolving to support growing widespread wireless technology usage.Recently, popular wireless standardized technology has progressed fromGlobal System for Mobile Communication (GSM) to Wideband Code DivisionMultiple Access (WCDMA) to Long Term Evolution (LTE). Cellular systemsare deployed in many frequency bands that are defined by a combinationof standardization organizations such as the 3d Generation PartnershipProject (3GPP) and government-sponsored agencies such as the FederalCommunications Commission (FCC). There are both frequency divisionduplex (FDD) and time division duplex (TDD) variants of frequencyallocations that are used in commercial cellular networks. In FDDsystems, the uplink and downlink use separate frequency bands at thesame time while, in TDD systems, the uplink and downlink use the samefrequencies at different times. Base station transceivers capable ofreceiving multiple frequency bands with a single signal path (i.e.,multi-band transceivers) have now become commonplace. These multi-bandtransceivers have the potential of advantageously lower cost and smallersize as compared to systems utilizing separate transceivers dedicated toeach band.

The inventors of the present disclosure realized that implementingbeamforming for cellular technology applications is challenging becausesignals of different frequencies (i.e., different carrier signals) areinvolved, as is the case with multi-band transceivers or when, evenwithin a single frequency band, a single operator may have licenses tonon-contiguous spectrum within the band. The inventors of the presentdisclosure further realized that, even without the challenge ofbeamforming in presence of different carrier signals, conventionalapproaches to performing beamforming individually for each antenna of aphased antenna array used in a cellular wireless system leave much to bedesired. For example, conventional approaches to performing beamformingin the analog domain do not allow for carrier-specific beamforming andone digital data path is shared by many power amplifiers which makesperforming digital predistortion (DPD) complex or altogether impossible,while conventional approaches to performing beamforming for cellularapplications in the digital domain result in RF transceivers that areextremely complex and oftentimes not feasible.

Embodiments of the present disclosure relate to cellular technologyapplications of beamforming performed in the digital domain (i.e.,digital beamforming). In one aspect, an RF system (e.g., an RFtransceiver) for performing digital beamforming on a per-carrier basisis disclosed, where different phase and/or amplitude adjustments areapplied to signals of different frequency ranges (e.g., to differentcarrier signals). In another aspect, an RF system (e.g., an RFtransceiver) for performing digital beamforming on a per-antenna basisis disclosed, where different phase and/or amplitude adjustments areapplied to signals transmitted from or received by different antennas ofan antenna array. As used herein, referring to digital beamforming asbeing performed on a “per-carrier basis” means that different carriersignals may be steered in different directions. On the other hand,referring to digital beamforming as being performed on a “per-antennabasis” means that each radiating element (e.g., each antenna elementdescribed herein) has an associated digital beamformer. This is incontrast to hybrid analog/digital beamforming in which a digitalbeamformer may be associated with many radiating elements, each of whichhas an analog beamformer associated with it. In some embodiments, an RFsystem may be configured to implement both digital beamforming on aper-carrier basis and digital beamforming on a per-antenna basis. The RFsystems disclosed herein allow implementing programmable beamforming forcellular applications in the digital domain in a manner that issignificantly less complex than conventional implementations.

As will be appreciated by one skilled in the art, aspects of the presentdisclosure, in particular aspects of per-carrier and/or per-antennadigital beamforming for cellular wireless communications as proposedherein, may be embodied in various manners—e.g., as a method, a system,a computer program product, or a computer-readable storage medium.Accordingly, aspects of the present disclosure may take the form of anentirely hardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Functionsdescribed in this disclosure may be implemented as an algorithm executedby one or more hardware processing units, e.g., one or moremicroprocessors of one or more computers. In various embodiments,different steps and portions of the steps of each of the methodsdescribed herein may be performed by different processing units.Furthermore, aspects of the present disclosure may take the form of acomputer program product embodied in one or more computer-readablemedium(s), preferably non-transitory, having computer-readable programcode embodied, e.g., stored, thereon. In various embodiments, such acomputer program may, for example, be downloaded (updated) to theexisting devices and systems (e.g., to the existing RF transmitters,receivers, transceivers, and/or their controllers, etc.) or be storedupon manufacturing of these devices and systems.

The following detailed description presents various descriptions ofspecific certain embodiments. However, the innovations described hereincan be embodied in a multitude of different ways, for example, asdefined and covered by the select examples. For example, variousembodiments of digital beamforming are described herein with referenceto TDD systems because beamforming may be easier to illustrate sincechannels of TDD systems are reciprocal (e.g., the same channels may beused for the downlink and the uplink signals so the same beamformerweights may be used for downlink and uplink). However, digitalbeamforming techniques disclosed herein are equally applicable to FDDsystems with modifications that would be apparent to a person ofordinary skill in the art based on the descriptions provided herein, allof which systems being, therefore, within the scope of the presentdisclosure.

In the following description, reference is made to the drawings, wherelike reference numerals can indicate identical or functionally similarelements. It will be understood that elements illustrated in thedrawings are not necessarily drawn to scale. Moreover, some embodimentscan incorporate any suitable combination of features from two or moredrawings. Further, it will be understood that certain embodiments caninclude more elements than illustrated in a drawing and/or a subset ofthe elements illustrated in a drawing. In general, while some drawingsprovided herein illustrate various aspects of RF systems configured toimplement per-carrier and/or per-antenna digital beamforming forcellular wireless communications, details of these systems may bedifferent in different embodiments. For example, further details shownin the drawings, such as the particular arrangement of the transceiversof the transceiver array 230, antennas of the antenna array 250, and therelation between the transceivers of the transceiver array 230 and theantennas of the antenna array 250 may be different in differentembodiments, with the illustrations of the present drawings providingonly some examples of how these components may be used together in an RFsystem. In another example, although some embodiments shown in thepresent drawings illustrate a certain number of components (e.g., acertain number of channels, transceivers and antennas), it is understoodthat these embodiments may be implemented in RF systems with any numberof these components in accordance with the descriptions provided herein.Furthermore, although the disclosure may discuss certain embodiments asone type of components of an RF system, it is understood that theembodiments disclosed herein may be implemented with different types ofcomponents of an RF system (e.g., beamformers described herein may betime domain beamformers or frequency domain beamformers, antenna arraysdescribed herein may be dynamic antenna arrays, passive antenna arrays,and the like).

The description may use the phrases “in an embodiment” or “inembodiments,” which may each refer to one or more of the same ordifferent embodiments. Unless otherwise specified, the use of theordinal adjectives “first,” “second,” and “third,” etc., to describe acommon object, merely indicate that different instances of like objectsare being referred to and are not intended to imply that the objects sodescribed must be in a given sequence, either temporally, spatially, inranking or in any other manner. Furthermore, for the purposes of thepresent disclosure, the phrase “A and/or B” or notation “A/B” means (A),(B), or (A and B), while the phrase “A, B, and/or C” means (A), (B),(C), (A and B), (A and C), (B and C), or (A, B, and C). As used herein,the notation “A/B/C” means (A, B, and/or C). The term “between,” whenused with reference to measurement ranges, is inclusive of the ends ofthe measurement ranges.

Various aspects of the illustrative embodiments are described usingterms commonly employed by those skilled in the art to convey thesubstance of their work to others skilled in the art. For example, theterm “connected” means a direct electrical connection between the thingsthat are connected, without any intermediary devices/components, whilethe term “coupled” means either a direct electrical connection betweenthe things that are connected, or an indirect electrical connectionthrough one or more passive or active intermediary devices/components.In another example, the terms “circuit” or “circuitry” (which may beused interchangeably) refer to one or more passive and/or activecomponents that are arranged to cooperate with one another to provide adesired function. Sometimes, in the present descriptions, the term“circuit” may be omitted (e.g., an upconverter and/or downconvertercircuit may be referred to simply as an upconverter and/ordownconverter, etc.). If used, the terms “substantially,”“approximately,” “about,” etc., may be used to generally refer to beingwithin +/−20% of a target value, e.g., within +/−10% of a target value,based on the context of a particular value as described herein or asknown in the art.

Example Cellular Wireless Communication System

FIG. 1 illustrates a wireless communication system 100, according tosome embodiments of the present disclosure, in which various embodimentsof per-carrier and/or per-antenna digital beamforming as describedherein may be implemented. The wireless communication system 100 mayinclude a base station 110 and a plurality of mobile stations, examplesof which are shown in FIG. 1 as a first mobile station 120, a secondmobile station 130, and a third mobile station 140. The base station 110may be coupled to a backend network (not shown) of the wirelesscommunication system and may provide communication between the mobilestations 120-140 and the backend network. In various embodiments, thewireless communication system 100 may include a plurality of basestations similar to the base station 110, which base stations may, e.g.,be arranged in cells, where only one base station 110 is shown in FIG. 1for simplicity and illustration purposes.

The base station 110 may support wireless communication with mobilestations 120-140 of various standard technologies as well as in multiplebands. For example, the base station 110 may support LTE, WCDMA, and GSMstandard communication. Each of the mobile stations 120-140 may supportany one or more of these standards. However, the use of these listedstandards is merely exemplary and other standards also may be supportedby different parts of the wireless communication system 100. The basestation 110 may transmit signals to the mobile stations 120-140 indownlink signals and receive signals from the mobile stations 120-140 inuplink signals. For example, the base station 110 may receive LTEcompliant signals from the first mobile station 120, WCDMA signals fromthe second mobile station 130, and GSM signals from the third mobilestation 140. The base station 110 may convert the received RF signals tobaseband signals, possibly by first converting them to intermediatefrequency (IF) signals, or low-IF signals, to demodulate and extractinformation from the received signals.

Example RF System for Implementing Per-Carrier and/or Per-AntennaDigital Beamforming

FIG. 2 provides a block diagram illustrating an example RF transceiversystem 200 configured to implement per-carrier and/or per-antennadigital beamforming for cellular wireless communications, according tosome embodiments of the present disclosure. The RF transceiver system200 may be interchangeably referred to as an “RF transceiver system”200. In various embodiments, the RF transceiver system 200 may beprovided in the base station 110 of FIG. 1 and/or in any of the mobilestations 120-140 of FIG. 1.

As shown in FIG. 2, the RF transceiver system 200 may include acontroller 210, a digital block 220, a transceiver array 230, and anantenna array 250.

In various embodiments, the controller 210 may either be included withinthe RF transceiver system 200, or be external, but communicativelycoupled, to the RF transceiver system 200. The controller 210 mayinclude any suitable device, configured to control operation of variousparts of the RF transceiver system 200. For example, in variousembodiments, the controller 210 may control one or more of the amountand the timing of phase shifting implemented in the RF transceiversystem 200, the amount and the timing of gain adjustments implemented inthe RF transceiver system 200, the frequencies of RF signals to whichthe baseband signals are to be upconverted for wireless transmission,etc. In some embodiments, the controller 210 may be configured to enablevarious components of the RF transceiver system 200 to function asdescribed herein in order to carry out per-carrier and/or per-antennadigital beamforming for cellular wireless communications. In someembodiments, the controller 210 may further control other aspects,components, and features of the RF transceiver system 200, describedherein. In some embodiments, the controller 210 may be implemented as,or include portions of, a data processing system shown in FIG. 7.

The digital block 220 may be configured to perform various functionsrelated to digital processing of the TX signals so that information canbe encoded in the TX signals and to perform various functions related todigital processing of the receive (RX) signals so that informationencoded in the RX signals can be extracted (the digital block 220 mayalso be referred to as a “digital signal processing circuit”). In someembodiments, the digital block 220 may be what is known in the art as“PHY,” which commonly refers to circuitry used to perform physical layerfunctions. In some embodiments of implementing per-carrier and/orper-antenna digital beamforming as described herein, the digital block220 may be configured to perform some adjustments of phase and/oramplitude of some TX or RX signals (i.e., phase/amplitude shifting maybe partially performed by the digital block 220). These embodiments willbe described in greater detail below.

As shown in FIG. 2, the digital block 220 may support a plurality ofchannels and include a plurality of input/output (I/O) ports, labeled inFIG. 2 as I/O1, I/O2, and so on, until I/O N (N may be an integergreater than 1), with a given I/O port of the digital block 220corresponding to a certain channel (the channels labeled in FIG. 2 asCH1, CH2, and so on, until CH N). Different channels of the digitalblock 220 may be coupled to different transceivers of the transceiverarray 230 and different antenna elements of the antenna array 250.

In some embodiments, the antenna array 250 may include a plurality ofantenna elements arranged in rows and columns. An example of such anarrangement is shown in FIG. 3, illustrating that the antenna array 250may include N*K antenna elements (labeled in FIG. 3 as antenna 11,antenna 12, antenna 13, etc.) arranged in N columns and K rows, where Kmay be any integer greater than 1. In the embodiment shown in FIGS. 2and 3, the variable N shown with reference to the antenna array 250 maybe the same N as refers to the number of channels supported by thedigital block 220. To that end, the antenna elements of the antennaarray 250 may be broken up in what may be referred to as an “antennacell” (labeled in FIG. 2 as an antenna cell 260-1, an antenna cell260-2, and so on, until an antenna cell 260-N), where each antenna cell260 may include a plurality of antenna elements of a different column,and different antenna cells may be coupled to different I/O ports of thedigital block 220. Thus, as shown in FIG. 2, in some embodiments, theantenna cell 260-1 may include antenna elements 11 through 1K of thefirst row of the antenna array 250, which antenna cell 260-1 may becoupled to the I/O 1 of the digital block 220; the antenna cell 260-2may include antenna elements 21 through 2K of the second row of theantenna array 250, which antenna cell 260-2 may be coupled to the I/O 2of the digital block 220, and so on. In other embodiments, the antennaarray 250 may include more or less than N columns of the antennaelements.

In general, each antenna element of the antenna array 250 may includeany suitable antenna element, or a plurality of antenna elements,configured to transmit and receive wireless RF signals in separate(e.g., non-overlapping and non-continuous) bands of frequencies, e.g.,in bands having a separation of, for example, several megahertz from oneanother. In some embodiments, each of at least some of the antennaelements may be a single multi-band antenna. In some embodiments, eachof at least some of the antenna elements may be a plurality ofband-specific antennas (i.e., a plurality of antennas each configured toreceive and transmit signals in a specific band of frequencies). In someembodiments, the antenna elements of the antenna array 250 may beconfigured to operate in a TDD mode. In other embodiments, the antennaelements of the antenna array 250 may be configured to operate in an FDDmode.

In some embodiments, for each antenna element of the antenna array 250,the RF transceiver system 200 may include a designated (i.e.,different/respective) transceiver. This is shown in FIG. 2 withdifferent transceivers of the transceiver array 230 being shown with thesame 2-digit reference numerals as those used for the antenna elementsof the antenna array 250 (where the first digit refers to the columnnumber and the second digit refers to the row number of a given antennaelement of the antenna array 250). When antenna elements of the antennaarray 250 are separated into antenna cells 260, the transceivers if thetransceiver array 230 may be similarly separated into transceiver cells240, labeled in FIG. 2 as a transceiver cell 240-1, a transceiver cell240-2, and so on, until a transceiver cell 240-N. Each transceiver cell240 may be coupled to a different antenna cell 260 and be coupled to adifferent I/O port of the digital block 220. Thus, as shown in FIG. 2,in some embodiments, the transceiver cell 240-1 may include transceivers11 through 1K of the transceiver array 230, which transceiver cell 240-1may be coupled between the antenna cell 260-1 and the I/O 1 of thedigital block 220; the transceiver cell 240-2 may include transceivers21 through 2K of the transceiver array 230, which transceiver cell 240-2may be coupled between the antenna cell 260-2 and the I/O 2 of thedigital block 220, and so on.

In the embodiments when each channel of the digital block 220 is coupledto a different sequence of a transceiver cell 240 and an antenna cell260 corresponding to a different column of the antenna elements of theantenna array 250, as shown in FIG. 2, the digital block 220 may beconfigured to perform phase shifting and amplitude adjustments withrespect to one direction/plane of the main beam for different columns ofthe antenna elements of the antenna array 250. For example, differentchannels of the digital block 220 may be configured to implementdifferent phase and amplitude adjustments for the horizontal plane ofthe beam. For example, with reference to the TX signals, the TX signalsoutput by the digital block 220 on different I/O ports may differ in theamount of phase and amplitude adjustments for the horizontal plane ofthe beam. The phase and amplitude adjustments for the vertical plane ofthe beam may then be implemented in the individual transceivers of thetransceiver cells coupled to the different I/O ports of the digitalblock 220.

The division of the antenna elements into antenna cells 260 and of thetransceivers into transceiver cells 240 is mainly functional and, inother embodiments, variations to that division are possible. Forexample, rows and columns as described herein may be interchanged.Having an individual transceiver corresponding/coupled to a givenantenna element of the antenna array 250 advantageously allowsperforming channel-specific beamforming, power amplifier (PA)-specificDPD, and other functions carefully tailored to a given antenna elementor a given antenna cell 260. However, in other embodiments, there may bea transceiver of the transceiver array 230 shared among two or moreantenna elements of the antenna array 250 (i.e., there may be lesstransceivers in the transceiver array 230 than antenna elements in theantenna array 250). In some embodiments, some or all antenna elements ofthe antenna array 250 may be implemented on a single die, substrate,wafer, or chip. In some embodiments, some or all transceivers of thetransceiver array 230 may be implemented on a single die, substrate,wafer, or chip.

Further details of the transceivers of the transceiver array 230 areshown in FIG. 4, providing a block diagram illustrating an example RFsystem 400 configured to implement per-antenna digital beamforming forcellular wireless communications, according to some embodiments of thepresent disclosure. The RF system 400 is an example of the RFtransceiver system 200 and, therefore, some elements shown in FIG. 4 arelabeled with the same reference numerals and letters as those shown inFIG. 2 so that descriptions of similar or analogous components providedfor one of the drawings do not have to be repeated for the other. The RFsystem 400 illustrates the digital block 220, with the I/O ports 1-N andchannels CH 1-N, as was shown in FIG. 2. For each of the channels, FIG.4 further illustrates blocks 420-1, 420-2, and so on, until 420-K. Eachblock 420 is a combination of a transceiver and a corresponding antennaelement of the transceiver array 230 and the antenna array 250 shown inFIG. 2. For example, the block 420-1 illustrates an antenna element 450,representing the antenna element antenna 11 shown in FIG. 2, and furtherillustrates some components of the transceiver 11 of FIG. 2. Inparticular, FIG. 4 illustrates that the transceiver 11 may include a TXpath that includes a digital TX adjuster 432, a digital upconverter(DUC) 434, and a digital-to-analog converter (DAC) 436. FIG. 4 furtherillustrates that the transceiver 11 may include a RX path that includesa digital RX adjuster 442, a digital downconverter (DDC) 444, and an ADC446. In some embodiments, the antenna element 450 may be used eitherwith the TX path or with the RX path of the transceiver 11, as is shownin FIG. 4 with a switch between the TX path and the antenna element 450being closed and a switch between the RX path and the antenna element450 being open (e.g., when the antenna 450 is configured to operate in aTDD mode). Individual components of other blocks 420 shown in FIG. 4 arenot individually labeled in order to not clutter the drawing, but eachof the other blocks 420 may be implemented as the block for thetransceiver 11 and the antenna element 11 of the block 420-11.

Turning to the details of the TX path of the representative block 420-1,the digital TX adjuster 432 may be configured to receive an input signalindicative of a signal transmitted by the digital block 220 from the I/O1 over the channel CH 1, which signal is indicative of a TX signal to betransmitted by the antenna element 450 of the block 420-1. The digitalTX adjuster 432 may be configured to generate an output signal byadjusting/modifying one or more of a phase and an amplitude of its inputsignal. Both the input and the output signals of the digital TX adjuster432 may be baseband signals. The DUC 434 is configured to perform anupconversion of a signal indicative of the output of the digital TXadjuster 432 to generate a corresponding signal but at a higherfrequency, e.g., upconverted to an intermediate frequency (IF).Conversion to an IF may be useful for several reasons. For example, whenseveral stages of filters are used, they can all be set to a fixedfrequency, which makes them easier to build and to tune. In someembodiments, the DUC 434 may be just one of several stages ofupconversion that may be implemented in the transceiver 11, with theother stages not shown in FIG. 4 in order to not clutter the drawing.Thus, in general, the DUC 434 may be configured to shift a signalindicative of the output of the digital TX adjuster 432 to a signal of ahigher frequency, where the former may but does not have to be abaseband signal, and the latter is a signal shifted to a higherfrequency. Furthermore, although not specifically shown in FIG. 4, theDUC 434 may be a quadrature upconverter, in which case it would includea first DUC and a second DUC, configured to provide upconverted signalsfor the in-phase (I) and quadrature (Q) paths, respectively (as is knownin the art, signals provided over I and Q paths signals having a 90degrees offset with respect to one another). A signal indicative of theoutput of the DUC 434 may then be converted to an analog signal by theDAC 436. Although no other components are shown in FIG. 4 between theDAC 436 and the antenna element 450, typically the TX path would includeother components in the path of the analog domain TX signal, such as ananalog filter, a further upconverter configured to perform anupconversion to the RF frequency, and a power amplifier, configured toamplify the TX signal before providing the TX signal to the antennaelement 450. Furthermore, additional components may be present betweenthe DUC 434 and the DAC 436, such as a DPD module, a crest-factorreduction (CFR) module, etc.

Turning to the details of the RX path of the representative block 420-1,an analog signal indicative of the output of the antenna element 450(i.e., a signal indicative of the signal received by the antenna element450) may then be converted to a digital signal by the ADC 446. Althoughno other components are shown in FIG. 4 between the antenna element 450and the ADC 436, typically the RX path would include other components inthe path of the analog domain RX signal, such as a low-noise amplifier(LNA), a downconverter configured to perform a downconversion from theRF frequency to a lower frequency (e.g., to the IF frequency), an analogfilter, etc. The DDC 444 is configured to perform a downconversion of asignal indicative of the output of the ADC 446 to generate acorresponding RX signal but at a lower frequency, e.g., downconvertedfrom the IF to baseband. In some embodiments, the DDC 444 may be justone of several stages of downconversion that may be implemented in thetransceiver 11, with the other stages not shown in FIG. 4 in order tonot clutter the drawing. Thus, in general, the DDC 434 may be configuredto shift an RX signal to a signal of a lower frequency, where the lattermay but does not have to be a baseband signal, and the former is asignal of a higher frequency. Furthermore, although not specificallyshown in FIG. 4, the DDC 444 may be a quadrature downconverter, in whichcase it would include a first DDC and a second DDC, configured toprovide downconverted signals for the I and Q paths, respectively.Furthermore, additional components may be present between the ADC 446and the DDC 444 (not shown in FIG. 4). The digital RX adjuster 442 maybe configured to receive an input signal indicative of an output of theDDC 444 and generate an output signal by adjusting/modifying one or moreof a phase and an amplitude of its input signal. Both the input and theoutput signals of the digital RX adjuster 442 may be baseband signals. Asignal indicative of the output of the digital RX adjuster 442 may thenbe provided to the digital block 220, via the I/O 1, over the channel CH1, which signal is indicative of an RX signal received by the antennaelement 450 of the block 420-1.

In general, the frequency of each DUC/DDC pair of the RF system 400(i.e., the frequency to which the DUC 434 performs the upconversion toand the frequency from which the DDC 444 performs the downconversion)may be arbitrary (e.g., may be programmable, e.g., user-defined). Forexample, different transceivers of the transceiver array 230 coupled toa given channel (e.g., the transceivers 11-1K coupled to the channel CH1) could include respective DUC/DDC pairs of different frequencies. Inanother example, at least some of the transceivers of the transceiverarray 230 coupled to two or more different channels could includeDUC/DDC pairs of the same frequency but steer the beams in differentdirections (by virtue of gain/amplitude adjustment using the digital TXadjuster 432 and/or the digital RX adjuster 442), allowing spatialfrequency re-use. The ability to individually control/set thefrequencies of different DUC/DDC pairs may advantageously allowincreasing network capacity, which is very valuable. The controller 210may be configured to control frequencies of the different DUC/DDC pairsof the individual transceivers of the RF system 400.

The architecture illustrated in FIG. 4 may allow performing digitalbeamforming on a per-antenna basis because different antenna elements450 have corresponding different TX and RX paths that can performprocessing of the TX and RX signals, respectively, for those antennaelements 450. In other words, in the RF system 400 there may be aone-to-one correspondence between the number of antenna elements 450 andthe number of the TX paths in all of the transceivers of the transceiverarray 230, and a one-to-one correspondence between the number of antennaelements 450 and the number of the RX paths in all of the transceiversof the transceiver array 230. In some embodiments, the digitalbeamforming may then be performed as follows (described with respect tothe TX path, and the beamforming for the RX path could be corresponding,e.g., reciprocal). In some embodiments, the TX signals provided by thedigital block 220 over different channels CH 1 through CH N could bedifferent in that the digital block 220 performed respectivephase/amplitude adjustments in the horizontal plane of the beam for theTX signals of the different channels. Individual digital TX adjusters432 in different transceivers of the transceiver array 230 may then beconfigured to implement respective phase/amplitude adjustments in thevertical plane of the beam for the TX signals to be transmitted bydifferent antennas of the antenna array 250, thus realizing aper-antenna digital beamforming. As is shown in FIG. 4, a set of blocks420-1 through 420-K coupled to a given channel may receive the sameinput signal (and sets of blocks 420-1 through 420-K coupled todifferent channels may receive different input signals), but thenimplement different phase/amplitude adjustments for the respectiveantenna 450 included within different ones of the blocks 420.

In some embodiments, digital beamforming may be implemented not only ona per-antenna basis but also on a per-carrier basis. An example of suchan implementation is shown in FIG. 5, providing a block diagramillustrating an example RF system 500 configured to implementper-carrier digital beamforming, e.g., on a per-carrier and per-antennabasis, for cellular wireless communications, according to someembodiments of the present disclosure. The RF system 500 is an exampleof the RF system 400 and, therefore, some elements shown in FIG. 5 arelabeled with the same reference numerals and letters as those shown inFIG. 4 so that descriptions of similar or analogous components providedfor one of the drawings do not have to be repeated for the other. Foreach of the blocks 420, FIG. 5 illustrates a digital TX adjuster 532, aDUC 534, a digital RX adjuster 542, and a DDC 544. Furthermore, for eachof the blocks 420, FIG. 5 further illustrates a CFR and/or DPD module572, a TRx calibration module 574, an analog upconverting mixer 576, apre-amplifier 578, a power amplifier 580, a circulator 582, an analogfilter 584, an LNA 586, and an analog downconverting mixer 588.

The digital TX adjuster 532 is similar to the digital TX adjuster 432except that now it is configured to perform phase/amplitude adjustmentson a per-carrier basis. The DUC 534 is similar to the DUC 434 exceptthat now it is configured to perform digital upconversion on aper-carrier basis. The digital RX adjuster 542 is similar to the digitalRX adjuster 442 except that now it is configured to performphase/amplitude adjustments on a per-carrier basis. The DDC 544 issimilar to the DDC 444 except that now it is configured to performdigital downconversion on a per-carrier basis. To highlight that thedigital TX adjuster 532, the DUC 534, the digital RX adjuster 542, andthe DDC 544 operate on a per-carrier basis, FIG. 5 illustrates multiplehorizontal lines going through these components. As used herein,describing something as operating on a per-carrier basis refers to theability to perform a certain functionality differently for differentcarrier signals. Thus, per-carrier beamforming means that the digital TXadjuster 532 and the digital RX adjuster 542 are configured to performphase/amplitude adjustments differently for different carriers.Per-carrier beamforming using the digital TX adjuster 532, the DUC 534,the digital RX adjuster 542, and the DDC 544 is described in greaterdetail with reference to FIG. 6.

The other components shown in FIG. 5 which were not shown in FIG. 4 areonly illustrated as an example of how the RF system 500 may beimplemented, but any of those components may be implemented as known inthe art. For example, the CFR and/or DPD module 572 may be configured toimplement any CFR and/or DPD algorithms to modify the TX signals to betransmitted by the antenna element 450 to compensate for variousnonlinear phenomena that may negatively affect the TX signals. The TRxcalibration module 574 may be configured to perform transceivercalibration such as DC offset removal, local oscillator leakagecancellation, and quadrature error correction. The analog upconvertingmixer 576 may be configured to perform analog upconversion of a signalindicative of the output of the DAC 436, e.g., using a local oscillator(LO) signal (the LO not specifically shown in FIG. 5). In someembodiments, the DAC 436 may be configured to perform the upconversionperformed by the analog upconverting mixer 576 (i.e., a separate analogupconverting mixer 576 as shown in FIG. 5 may be omitted). Thepre-amplifier 578 may be configured to perform the first stage and thePA 580 is configured to perform the second stage of power amplification(in other embodiments, the power amplification may be performed in asingle stage, or in more than 2 stages). The circulator 582 may beconfigured to separate TX and RX signals when the RF system operates ina TDD mode. The analog filter 584 is configured to perform the analogdomain filtering of the TX signals to be transmitted by the antennaelement 450 and/or of the RX signal received by the antenna element 450.The LNA 586 is configured to amplify the RX signals in the analogdomain. The analog downconverting mixer 588 may be configured to performanalog downconversion of the RX signal, e.g., using the LO signal. Insome embodiments, the ADC 446 may be configured to perform thedownconversion performed by the analog downconverting mixer 588 (i.e., aseparate analog downconverting mixer 588 as shown in FIG. 5 may beomitted).

Per-carrier digital beamforming may be described in greater detail withreference to FIG. 6, providing a block diagram illustrating per-carrierbeamforming in a TX path of a K-channel transceiver cell of an RF system600, according to some embodiments of the present disclosure. The RFsystem 600 is an example of the RF system 500 and, therefore, someelements shown in FIG. 6 are labeled with the same reference numeralsand letters as those shown in FIG. 5 so that descriptions of similar oranalogous components provided for one of the drawings do not have to berepeated for the other. In particular, FIG. 6 illustrates only thecomponents associated with one of the channels of the digital block 220of the RF system 500, e.g., channel CH 1. Thus, FIG. 6 illustrates thedetails of the transceivers 11-1K of the transceiver cell 240-1, coupledto, respectively, antenna elements 11-1K of the antenna cell 260-1.These descriptions are equally applicable to other channels of thedigital block 220. While the descriptions of FIG. 6 are provided for theTX path, these descriptions are equally applicable to the RX path withmodifications that would be apparent to a person of ordinary skill inthe art because of the reciprocal nature of the TX and RX paths, all ofwhich embodiments being within the scope of the present disclosure.

Each channel of the digital block 220 may be configured to supportmultiple carriers, e.g., carriers C1 and C2. Although FIG. 6 illustratesonly 2 carriers, in other embodiments, these descriptions may easily beextended to cover any number of 2 or more carriers, all of whichembodiments being within the scope of the present disclosure. Thecarriers C1 and C2 may be of any frequency and bandwidth, depending onthe wireless technology of the RF system 600. For example, in LTEsystems, the carrier bandwidth varies between 1.4 MHz and 20 MHz, whilein 5G new radio (NR) systems, the widest sub-6 GHz (FR1) carrierbandwidth may be as large as 100 MHz. The digital block 220 may beconfigured to prepare signals C1 and C2 for transmission and providethose signals, via the I/O 1 and via channel CH 1 to each of thetransceivers of the transceiver cell 240-1.

In some embodiments, the C1 and C2 digital signals may be provided fromthe digital block 220 to the transceiver cell 240-1 over a serialinterface. To that end, as shown in FIG. 6, the digital block 220 mayinclude a serializer 622 configured to serialize the signals C1 and C2provided thereto in parallel, to generate a signal that includes C1 andC2, which signal may then be provided over a serial interface of CH1 tothe transceiver cell 240-1. The transceiver cell 240-1 may include ade-serializer 624, configured to reconstruct the individual signals C1and C2 and provide each of the signals C1 and C2 to each of thetransceivers 11-1K. Such embodiments may be advantageous in terms of areduced chip-to-chip interface bandwidth requirements, e.g., when thedigital block 220 is implemented on one chip, and the transceiver cell240-1 is implemented on another chip. However, in other embodiments, theinterface of CH 1 does not have to be serial, and the different carriersignals may be provided from the digital block 220 to the transceivercell 240-1 in parallel.

Whether provided over a serial or a parallel interface of CH1, withinthe transceiver cell 240-1, each of the carrier signals C1 and C2 isprovided to each of the transceivers 11-1K. In particular, the digitalTX adjusters 532 of different ones of the transceivers 11-1K may beconfigured to receive the carrier signals C1 and C2 (or signalindicative thereof). The digital TX adjuster 532 of a given transceivermay be configured to process the different carrier signals separately,e.g., in parallel. To that end, as shown in FIG. 6, the digital TXadjuster 532 may include a phase shifter 631-1 and a gain adjuster632-1, configured to perform, respectively, phase and amplitudeadjustments of the TX signal for the first carrier C1. As further shownin FIG. 6, the digital TX adjuster 532 may also include a phase shifter631-2 and a gain adjuster 632-2, configured to perform, respectively,phase and amplitude adjustments of the TX signal for the second carrierC2. While FIG. 6 illustrates that the TX signal for each carrier isfirst provided to the phase shifter 631 and then to the gain adjuster632, in other embodiments, this order may be reversed for some or allcarriers processed by some or all transceivers. Together, the phaseshifter 631-1 and the gain adjuster 632-1 may be seen as a first digitaladjuster (of the digital TX adjuster 532), configured to generate afirst adjuster output signal by modifying one or more of a phase and anamplitude of the first adjuster input signal (i.e., the input signalindicative of the TX signal C1). Similarly, together, the phase shifter631-2 and the gain adjuster 632-2 may be seen as a second digitaladjuster (of the digital TX adjuster 532), configured to generate asecond adjuster output signal by modifying one or more of a phase and anamplitude of the second adjuster input signal (i.e., the input signalindicative of the TX signal C2).

In some embodiments, the input and the output signals from the first andsecond digital adjusters are baseband signals. Thus, signals C1 and C2provided to each of the transceivers 11-1K may be baseband signals,indicative of TX signals in first and second RF frequency bands to whichthey will be upconverter later on, while signals C1′ and C2′ output byeach of the transceivers 11-1K may still be baseband signals, but withphase/amplitude adjustment in accordance with the desired beamforming.The input signal C1 provided to each of the transceivers of a giventransceiver cell (e.g., to the transceivers 11-1K of the transceivercell 240-1) may be the same input signal, but the output signal C1generated by the digital TX adjusters 532 of different transceivers (inparticular, generated by the phase shifter 631-1 and the gain adjuster632-1 of different transceivers) may be different because of differentphase/amplitude adjustments applied to the input signal C1 within thedigital TX adjusters 532 of different transceivers. Similarly, the inputsignal C2 provided to each of the transceivers of a given transceivercell (e.g., to the transceivers 11-1K of the transceiver cell 240-1) maybe the same input signal, but the output signal C2 generated by thedigital TX adjusters 532 of different transceivers (in particular,generated by the phase shifter 631-2 and the gain adjuster 632-2 ofdifferent transceivers) may be different because of differentphase/amplitude adjustments applied to the input signal C2 within thedigital TX adjusters 532 of different transceivers.

As further shown in FIG. 6, the phase/amplitude adjusted signals C1′ andC2′ are then provided to respective DUCs, e.g., to a DUC 634-1 and a DUC634-2, respectively. Together, the DUC 634-1 and the DUC 634-2 may beseen as the DUC 534, described above. In particular, each of the DUCs634-1 and DUC 634-2 may be configured to perform the upconversion as wasdescribed above with reference to the DUC 534, except that the DUCs634-1 and DUC 634-2 are configured to receive baseband TX signals fordifferent carriers. The DUCs 634-1 and 634-2 may be configured to applyfrequency shifts to the baseband signals C1′ and C2′, respectively. Forexample, in some embodiments, the DUC 634-1 may shift the signal C1′negatively in frequency, while the DUC 634-2 may shift the signal C2′positively in frequency (or the other way around). At this point, thecomposite signal of the frequency-shifted C1′ and C2′ is still in adigital I/O format of quadrature processing.

As also shown in FIG. 6, each of the transceivers may further include acombiner 636, configured to combine the outputs of the multiple DUCs 634of that transceiver (e.g., the output of the DUC 634-1 and the DUC634-2) to generate a composite signal C12. The composite signal C12 maybe a baseband signal centered at 0 the DC, with TX signals of variouscarriers arranged in a way that corresponds to their relativearrangement in the RF. Said differently, the DUCs 634 of a giventransceiver of the transceiver cell 240-1 may be configured to upconvertand frequency shift the signals C1′ and C2′ so that, when arranged in acomposite signal (e.g., the signal C12 generated by the combiner 636),the arrangement of the signals C1′ and C2′ along an axis measuringfrequency is such that the composite signal C12 is still within thetransceiver's baseband bandwidth (e.g., C1′ and C2′ of the compositesignal C12 may be centered at DC, but in other embodiments they do nothave to be centered at DC as long as they are somewhere within thetransceiver's baseband bandwidth) and the relative arrangement of thesignals C1′ and C2′ corresponds to the relative arrangement of thesignals C1′ and C2′ when they are converted to RF.

The composite signals C12 may then proceed through the signal chain oftheir respective transceivers (i.e., the signal chain of thetransceivers after the DUC 534) until they are converted to analog RFsignals centered at Fc and transmitted by the respective antennaelements associated with the transceivers. As described above, invarious embodiments, said conversion may be done in a variety of waysincluding direct synthesis with an RF DAC (e.g., the DAC 436),conversion to analog via a pair of quadrature baseband DACs followed byupconversion to RF via quadrature mixers or in two or more steps byconverting to an IF frequency in the DAC followed by conversion to Fc bya mixer (e.g., the mixer 576).

In FIG. 6, when TX signals are separate for carriers C1 and C2, thosefor the carrier C1 are shown with black dotted arrows, while those forthe carrier for C2 are shown with gray arrows (i.e., arrows going to theserializer 622, arrows going to and from the phase shifters 631, arrowsgoing to and from the gain adjusters 632, and arrows going to and fromthe phase shifters 631, arrows going to and from the DUCs 634).

To summarize, together, each of the K channels of a given transceivercell 240 (where the K channels may include the transceiver portions ofthe block 420-1 through 420-K, shown in FIGS. 4 and 5), is configured torealize desired phase shift and gain adjustment. Taken together, the Kphase and gain adjustments form a beam at RF. Within each of the Kchannels of a given transceiver cell 240, each carrier may have adedicated phase and amplitude adjustments, with 2 carriers shown in theillustration of FIG. 6 but the number of carriers may be arbitrary. Insome embodiments, the phase and gain adjustment weights may be stored ina loop-up table associated with the transceiver array 230 or may beprovided to the transceiver array 230.

Example Data Processing System

FIG. 7 provides a block diagram illustrating an example data processingsystem 700 that may be configured to implement, or controlimplementation of, at least portions of the per-carrier and/orper-antenna digital beamforming for cellular wireless communications asdescribed herein, according to some embodiments of the presentdisclosure. For example, the controller 210 may include at leastportions of the data processing system 700.

As shown in FIG. 7, the data processing system 700 may include at leastone processor 702, e.g., a hardware processor 702, coupled to memoryelements 704 through a system bus 706. As such, the data processingsystem may store program code within memory elements 704. Further, theprocessor 702 may execute the program code accessed from the memoryelements 704 via a system bus 706. In one aspect, the data processingsystem may be implemented as a computer that is suitable for storingand/or executing program code. It should be appreciated, however, thatthe data processing system 700 may be implemented in the form of anysystem including a processor and a memory that is capable of performingthe functions described within this disclosure.

In some embodiments, the processor 702 can execute software or analgorithm to perform the activities as discussed in the presentdisclosure, in particular activities related to per-carrier and/orper-antenna digital beamforming for cellular wireless RF systems asdescribed herein. The processor 702 may include any combination ofhardware, software, or firmware providing programmable logic, includingby way of non-limiting example a microprocessor, a digital signalprocessor (DSP), a field-programmable gate array (FPGA), a programmablelogic array (PLA), an application specific integrated circuit (IC)(ASIC), or a virtual machine processor. The processor 702 may becommunicatively coupled to the memory element 704, for example in adirect-memory access (DMA) configuration, so that the processor 702 mayread from or write to the memory elements 704.

In general, the memory elements 704 may include any suitable volatile ornon-volatile memory technology, including double data rate (DDR) randomaccess memory (RAM), synchronous RAM (SRAM), dynamic RAM (DRAM), flash,read-only memory (ROM), optical media, virtual memory regions, magneticor tape memory, or any other suitable technology. Unless specifiedotherwise, any of the memory elements discussed herein should beconstrued as being encompassed within the broad term “memory.” Theinformation being measured, processed, tracked or sent to or from any ofthe components of the data processing system 700 could be provided inany database, register, control list, cache, or storage structure, allof which can be referenced at any suitable timeframe. Any such storageoptions may be included within the broad term “memory” as used herein.Similarly, any of the potential processing elements, modules, andmachines described herein should be construed as being encompassedwithin the broad term “processor.” Each of the elements shown in thepresent figures, e.g., the transceivers of the transceiver array 230 (orany individual components of these transceivers), antennas of theantenna array 250, or other elements/components shown in FIGS. 2-6, canalso include suitable interfaces for receiving, transmitting, and/orotherwise communicating data or information in a network environment sothat they can communicate with, e.g., the data processing system 700.

In certain example implementations, mechanisms for per-carrier and/orper-antenna digital beamforming for cellular wireless communications asoutlined herein may be implemented by logic encoded in one or moretangible media, which may be inclusive of non-transitory media, e.g.,embedded logic provided in an ASIC, in DSP instructions, software(potentially inclusive of object code and source code) to be executed bya processor, or other similar machine, etc. In some of these instances,memory elements, such as e.g., the memory elements 704 shown in FIG. 7,can store data or information used for the operations described herein.This includes the memory elements being able to store software, logic,code, or processor instructions that are executed to carry out theactivities described herein. A processor can execute any type ofinstructions associated with the data or information to achieve theoperations detailed herein. In one example, the processors, such ase.g., the processor 702 shown in FIG. 7, could transform an element oran article (e.g., data) from one state or thing to another state orthing. In another example, the activities outlined herein may beimplemented with fixed logic or programmable logic (e.g.,software/computer instructions executed by a processor) and the elementsidentified herein could be some type of a programmable processor,programmable digital logic (e.g., an FPGA, a DSP, an erasableprogrammable read-only memory (EPROM), an electrically erasableprogrammable read-only memory (EEPROM)) or an ASIC that includes digitallogic, software, code, electronic instructions, or any suitablecombination thereof.

The memory elements 704 may include one or more physical memory devicessuch as, for example, local memory 708 and one or more bulk storagedevices 710. The local memory may refer to RAM or other non-persistentmemory device(s) generally used during actual execution of the programcode. A bulk storage device may be implemented as a hard drive or otherpersistent data storage device. The processing system 700 may alsoinclude one or more cache memories (not shown) that provide temporarystorage of at least some program code in order to reduce the number oftimes program code must be retrieved from the bulk storage device 710during execution.

As shown in FIG. 7, the memory elements 704 may store an application718. In various embodiments, the application 718 may be stored in thelocal memory 708, the one or more bulk storage devices 710, or apartfrom the local memory and the bulk storage devices. It should beappreciated that the data processing system 700 may further execute anoperating system (not shown in FIG. 7) that can facilitate execution ofthe application 718. The application 718, being implemented in the formof executable program code, can be executed by the data processingsystem 700, e.g., by the processor 702. Responsive to executing theapplication, the data processing system 700 may be configured to performone or more operations or method steps described herein.

Input/output (I/O) devices depicted as an input device 712 and an outputdevice 714, optionally, can be coupled to the data processing system.Examples of input devices may include, but are not limited to, akeyboard, a pointing device such as a mouse, or the like. Examples ofoutput devices may include, but are not limited to, a monitor or adisplay, speakers, or the like. In some embodiments, the output device714 may be any type of screen display, such as plasma display, liquidcrystal display (LCD), organic light emitting diode (OLED) display,electroluminescent (EL) display, or any other indicator, such as a dial,barometer, or light emitting diodes (LEDs). In some implementations, thesystem may include a driver (not shown) for the output device 714. Inputand/or output devices 712, 714 may be coupled to the data processingsystem either directly or through intervening I/O controllers.

In an embodiment, the input and the output devices may be implemented asa combined input/output device (illustrated in FIG. 7 with a dashed linesurrounding the input device 712 and the output device 714). An exampleof such a combined device is a touch sensitive display, also sometimesreferred to as a “touch screen display” or simply “touch screen”. Insuch an embodiment, input to the device may be provided by a movement ofa physical object, such as e.g., a stylus or a finger of a user, on ornear the touch screen display.

A network adapter 716 may also, optionally, be coupled to the dataprocessing system to enable it to become coupled to other systems,computer systems, remote network devices, and/or remote storage devicesthrough intervening private or public networks. The network adapter maycomprise a data receiver for receiving data that is transmitted by saidsystems, devices and/or networks to the data processing system 700, anda data transmitter for transmitting data from the data processing system700 to said systems, devices and/or networks. Modems, cable modems, andEthernet cards are examples of different types of network adapter thatmay be used with the data processing system 700.

Select Examples

The following paragraphs provide various examples of the embodimentsdisclosed herein.

Example 1 provides a digital beamforming device for a cellular RFantenna apparatus. The device includes a first digital adjuster and asecond digital adjuster. The first digital adjuster (e.g., 631-1 and632-1 of the transceiver 11 shown in FIG. 6) is configured to receive afirst adjuster input signal indicative of a transmit (TX) signal in afirst frequency band (C1), and to generate a first adjuster outputsignal (Cr) by modifying one or more of a phase and an amplitude of thefirst adjuster input signal, where each of the first adjuster inputsignal and the first adjuster output signal is a digital signal. Thesecond digital adjuster (e.g., 631-2 and 632-2 of the transceiver 11shown in FIG. 6) is configured to receive a second adjuster input signalindicative of a TX signal in a second frequency band (C2), where thesecond frequency band is different from the first frequency band, and togenerate a second adjuster output signal (C2′) by modifying one or moreof a phase and an amplitude of the second adjuster input signal, whereeach of the second adjuster input signal and the second adjuster outputsignal is a digital signal. The device further includes a combiner(e.g., 636 of the transceiver 11 shown in FIG. 6), configured to combinea signal indicative of the first adjuster output and a signal indicativeof the second adjuster output into a composite TX signal (e.g., C12 inthe transceiver 11 shown in FIG. 6), where an RF signal based on thecomposite TX signal is to be wirelessly transmitted by an antennaelement (e.g., antenna 11 shown in FIG. 6).

Example 2 provides the device according to example 1, further includinga de-serializer, including at least an input port and a first and asecond output ports. The de-serializer is configured to receive, at theinput port of the de-serializer, a composite input signal, the compositeinput signal including one or more signal components indicative of thefirst adjuster input signal and further including one or more signalcomponents indicative of the second adjuster input signal. Thede-serializer is further configured to output at the first output port asignal indicative of the first adjuster input signal and output at thesecond output port a signal indicative of the second adjuster inputsignal.

Example 3 provides the device according to examples 1 or 2, where thedevice is configured to receive the first adjuster input signal and thesecond adjuster input signal from a digital block, via a digitalinterface.

Example 4 provides the device according to any one of the precedingexamples, where the combiner is a first combiner, the composite TXsignal is a first composite TX signal, and the antenna element is afirst antenna element. The device further includes a third digitaladjuster and a fourth digital adjuster. The third digital adjuster(e.g., 631-1 and 632-1 of the transceiver 12 shown in FIG. 6) isconfigured to receive the first adjuster input signal (i.e., the sameinput signal as that received by the first digital adjuster), and togenerate a third adjuster output signal by modifying one or more of thephase and the amplitude of the first adjuster input signal, where thethird adjuster output signal is a digital signal and where the thirdadjuster output signal is different from the first adjuster outputsignal (i.e., the first and third digital adjusters are configured toperform different phase/amplitude adjustment). The fourth digitaladjuster (e.g., 631-2 and 632-2 of the transceiver 12 shown in FIG. 6)is configured to receive the second adjuster input signal (i.e., thesame input signal as that received by the second digital adjuster), andto generate a fourth adjuster output signal by modifying one or more ofthe phase and the amplitude of the second adjuster input signal, wherethe fourth adjuster output signal is a digital signal and where thefourth adjuster output signal is different from the second adjusteroutput signal (i.e., the second and fourth digital adjusters areconfigured to perform different phase/amplitude adjustment). The devicefurther includes a second combiner (e.g., 636 of the transceiver 12shown in FIG. 6), configured to combine a signal indicative of the thirdadjuster output and a signal indicative of the fourth adjuster outputinto a second composite TX signal (e.g., C12 in the transceiver 12 shownin FIG. 6), where an RF signal based on the second composite TX signalis to be wirelessly transmitted by a second antenna element (e.g.,antenna 12 shown in FIG. 6).

Example 5 provides the device according to example 4, where a phase andan amplitude of the first adjuster output signal are indicative ofbeamforming for the TX signal in the first frequency band to betransmitted by the first antenna element, a phase and an amplitude ofthe second adjuster output signal are indicative of beamforming for theTX signal in the second frequency band to be transmitted by the firstantenna element, a phase and an amplitude of the third adjuster outputsignal are indicative of beamforming for the TX signal in the firstfrequency band to be transmitted by the second antenna element, and aphase and an amplitude of the fourth adjuster output signal areindicative of beamforming for the TX signal in the second frequency bandto be transmitted by the second antenna element.

Example 6 provides the device according to example 5, where each of thebeamforming for the TX signal in the first frequency band to betransmitted by the first antenna element, the beamforming for the TXsignal in the second frequency band to be transmitted by the firstantenna element, the beamforming for the TX signal in the firstfrequency band to be transmitted by the second antenna element, and thebeamforming for the TX signal in the second frequency band to betransmitted by the second antenna element is beamforming along a firstplane of a pair of a horizontal plane and a vertical plane for the TXsignal.

Example 7 provides the device according to example 6, where the phaseand the amplitude of the first adjuster input signal are indicative ofbeamforming along a second plane of the pair for the TX signal in thefirst frequency band to be transmitted either by the first antennaelement or the second antenna element, and the phase and the amplitudeof the second adjuster input signal are indicative of beamforming alongthe second plane for the TX signal in the second frequency band to betransmitted either by the first antenna element or the second antennaelement.

Example 8 provides the device according to any one of the precedingexamples, further including a first digital upconverter (DUC),configured to perform digital upconversion to covert the first adjusteroutput to a first upconverted adjuster output; and a second DUC,different from the first DUC, configured to perform digital upconversionto covert the second adjuster output to a second upconverted adjusteroutput, where the combiner is configured to combine a signal indicativeof the first upconverted adjuster output and a signal indicative of thesecond upconverted adjuster output into the composite TX signal.

Example 9 provides the device according to example 8, where thecomposite TX signal is an intermediate frequency (IF) digital signal.

Example 10 provides the device according to any one of the precedingexamples, where each of the first adjuster input signal, the firstadjuster output signal, the second adjuster input signal, and the secondadjuster output signal is a baseband signal.

Example 11 provides a digital beamforming device for a cellular RFantenna apparatus. The device includes a digital block, configured toapply a first modification to a transmit (TX) signal to generate a firstTX signal, and to apply a second modification to the TX signal togenerate a second TX signal, where applying each of the firstmodification and the second modification includes modifying one or moreof a phase and an amplitude of the TX signal to reflect beamformingalong a first plane of a pair of a horizontal plane and a vertical planeof a beam, and where the first modification is different from the secondmodification (different in one or more of a phase and an amplitude). Thedevice further includes a first transceiver, configured to apply a firsttransceiver modification to the first TX signal by modifying one or moreof a phase and an amplitude of the first TX signal to reflectbeamforming along a second plane of the pair; and a second transceiver,configured to apply a second transceiver modification to the second TXsignal by modifying one or more of a phase and an amplitude of thesecond TX signal to reflect beamforming along the second plane of thepair.

Example 12 provides the device according to example 11, where the firsttransceiver is one of a first plurality of transceivers of a firsttransceiver cell, where each transceiver of the first plurality oftransceivers is configured to apply a respective/corresponding (i.e.,different) first transceiver modification to the first TX signal bymodifying one or more of the phase and the amplitude of the first TXsignal to reflect beamforming along the second plane of the pair, andthe second transceiver is one of a second plurality of transceivers of asecond transceiver cell, where each transceiver of the second pluralityof transceivers is configured to apply a respective/corresponding (i.e.,different) second transceiver modification to the second TX signal bymodifying one or more of the phase and the amplitude of the second TXsignal to reflect beamforming along the second plane of the pair.

Example 13 provides the device according to example 12, where eachtransceiver of the first plurality of transceivers and the secondplurality of transceivers is coupled to a respective/corresponding(i.e., different) antenna element. In this manner, digital beamformingmay be performed on a per-antenna basis.

Example 14 provides the device according to examples 12 or 13, whereeach transceiver of the first plurality of transceivers and the secondplurality of transceivers includes a digital upconverter (DUC) and adigital downconverter (DDC), and the device further includes acontroller, configured to set frequencies of a pair of the DUC and theDDC for each transceiver of the first plurality of transceivers and thesecond plurality of transceivers on a per-transceiver basis.

Example 15 provides the device according to any one of examples 11-14,where the TX signal includes a first carrier component (C1) in a firstfrequency band and a second carrier component (C2) in a second frequencyband, the second frequency band being different from the first frequencyband, the first transceiver modification applied by the firsttransceiver to the first TX signal includes different modificationsapplied to the first and second carrier components of the first TXsignal. In this manner, digital beamforming may be performed on aper-carrier basis.

Example 16 provides the device according to any one of examples 11-15,where each of the TX signal, the first TX signal, and the second TXsignal is a digital baseband signal.

Example 17 provides an RF transceiver device. The device includes afirst transceiver, configured to receive a first transmit (TX) signal,where the first TX signal is a TX signal to which a first modificationhas been applied; and a second transceiver, configured to receive asecond TX signal, where the second TX signal is a TX signal to which asecond modification has been applied. In such a device, each of thefirst modification and the second modification includes a modificationof one or more of a phase and an amplitude of the TX signal to reflectbeamforming along a first plane of a pair of a horizontal plane and avertical plane of a beam, the first modification is different from thesecond modification (different in one or more of a phase and anamplitude), the first transceiver is configured to apply a firsttransceiver modification to the first TX signal by modifying one or moreof a phase and an amplitude of the first TX signal to reflectbeamforming along a second plane of the pair, and the second transceiveris configured to apply a second transceiver modification to the secondTX signal by modifying one or more of a phase and an amplitude of thesecond TX signal to reflect beamforming along the second plane of thepair.

Example 18 provides the device according to example 17, where the firsttransceiver is one of a first plurality of transceivers of a firsttransceiver cell of the apparatus, where each transceiver of the firstplurality of transceivers is configured to apply arespective/corresponding (i.e., different) first transceivermodification to the first TX signal by modifying one or more of thephase and the amplitude of the first TX signal to reflect beamformingalong the second plane of the pair, and the second transceiver is one ofa second plurality of transceivers of a second transceiver cell of theapparatus, where each transceiver of the second plurality oftransceivers is configured to apply a respective/corresponding (i.e.,different) second transceiver modification to the second TX signal bymodifying one or more of the phase and the amplitude of the second TXsignal to reflect beamforming along the second plane of the pair.

Example 19 provides the device according to example 18, where eachtransceiver of the first plurality of transceivers and the secondplurality of transceivers is coupled to a respective/corresponding(i.e., different) antenna element. In this manner, digital beamformingmay be performed on a per-antenna basis.

Example 20 provides the device according to any one of examples 17-19,where the TX signal includes a first carrier component (C1) in a firstfrequency band and a second carrier component (C2) in a second frequencyband, the second frequency band being different from the first frequencyband, the first transceiver modification applied by the firsttransceiver to the first TX signal includes different modificationsapplied to the first and second carrier components of the first TXsignal. In this manner, digital beamforming may be performed on aper-carrier basis.

Variations and Implementations

While embodiments of the present disclosure were described above withreferences to exemplary implementations as shown in FIGS. 1-7, a personskilled in the art will realize that the various teachings describedabove are applicable to a large variety of other implementations.

In the discussions of the embodiments above, components of a system,such as e.g., phase adjusters, mixers, up/down converters, and/or othercomponents can readily be replaced, substituted, or otherwise modifiedin order to accommodate particular circuitry needs. Moreover, it shouldbe noted that the use of complementary electronic devices, hardware,software, etc. offer an equally viable option for implementing theteachings of the present disclosure related to per-carrier and/orper-antenna digital beamforming for cellular wireless communications.

Parts of various systems for implementing per-carrier and/or per-antennadigital beamforming for cellular wireless communications as proposedherein can include electronic circuitry to perform the functionsdescribed herein. In some cases, one or more parts of the system can beprovided by a processor specially configured for carrying out thefunctions described herein. For instance, the processor may include oneor more application specific components, or may include programmablelogic gates which are configured to carry out the functions describeherein. The circuitry can operate in analog domain, digital domain, orin a mixed-signal domain. In some instances, the processor may beconfigured to carrying out the functions described herein by executingone or more instructions stored on a non-transitory computer-readablestorage medium.

In one example embodiment, any number of electrical circuits of thepresent figures may be implemented on a board of an associatedelectronic device. The board can be a general circuit board that canhold various components of the internal electronic system of theelectronic device and, further, provide connectors for otherperipherals. More specifically, the board can provide the electricalconnections by which the other components of the system can communicateelectrically. Any suitable processors (inclusive of DSPs,microprocessors, supporting chipsets, etc.), computer-readablenon-transitory memory elements, etc. can be suitably coupled to theboard based on particular configuration needs, processing demands,computer designs, etc. Other components such as external storage,additional sensors, controllers for audio/video display, and peripheraldevices may be attached to the board as plug-in cards, via cables, orintegrated into the board itself. In various embodiments, thefunctionalities described herein may be implemented in emulation form assoftware or firmware running within one or more configurable (e.g.,programmable) elements arranged in a structure that supports thesefunctions. The software or firmware providing the emulation may beprovided on non-transitory computer-readable storage medium comprisinginstructions to allow a processor to carry out those functionalities.

In another example embodiment, the electrical circuits of the presentfigures may be implemented as stand-alone modules (e.g., a device withassociated components and circuitry configured to perform a specificapplication or function) or implemented as plug-in modules intoapplication specific hardware of electronic devices. Note thatparticular embodiments of the present disclosure may be readily includedin a system on chip (SOC) package, either in part, or in whole. An SOCrepresents an IC that integrates components of a computer or otherelectronic system into a single chip. It may contain digital, analog,mixed-signal, and often RF functions: all of which may be provided on asingle chip substrate. Other embodiments may include a multi-chip-module(MCM), with a plurality of separate ICs located within a singleelectronic package and configured to interact closely with each otherthrough the electronic package.

It is also imperative to note that all of the specifications,dimensions, and relationships outlined herein (e.g., the number ofcomponents of the transceivers shown in FIGS. 2, 4, 5, and 6, and/or thenumber of the carrier signal bands shown in FIG. 6, etc.) have only beenoffered for purposes of example and teaching only. Such information maybe varied considerably without departing from the spirit of the presentdisclosure, or the scope of the appended claims. The specificationsapply only to one non-limiting example and, accordingly, they should beconstrued as such. In the foregoing description, example embodimentshave been described with reference to particular processor and/orcomponent arrangements. Various modifications and changes may be made tosuch embodiments without departing from the scope of the appendedclaims. The description and drawings are, accordingly, to be regarded inan illustrative rather than in a restrictive sense.

Note that with the numerous examples provided herein, interaction may bedescribed in terms of two, three, four, or more electrical components.However, this has been done for purposes of clarity and example only. Itshould be appreciated that the system can be consolidated in anysuitable manner. Along similar design alternatives, any of theillustrated components, modules, and elements of the present FIGS. maybe combined in various possible configurations, all of which are clearlywithin the broad scope of the present disclosure. In certain cases, itmay be easier to describe one or more of the functionalities of a givenset of flows by only referencing a limited number of electricalelements. It should be appreciated that the electrical circuits of thepresent figures and its teachings are readily scalable and canaccommodate a large number of components, as well as morecomplicated/sophisticated arrangements and configurations. Accordingly,the examples provided should not limit the scope or inhibit the broadteachings of the electrical circuits as potentially applied to a myriadof other architectures.

Note that in the present disclosure, references to various features(e.g., elements, structures, modules, components, steps, operations,characteristics, etc.) included in “one embodiment”, “exampleembodiment”, “an embodiment”, “another embodiment”, “some embodiments”,“various embodiments”, “other embodiments”, “alternative embodiment”,and the like are intended to mean that any such features are included inone or more embodiments of the present disclosure, but may or may notnecessarily be combined in the same embodiments.

It is also important to note that the functions related to per-carrierand/or per-antenna digital beamforming for cellular wirelesscommunications as proposed herein illustrate only some of the possiblefunctions that may be executed by, or within, system illustrated in thepresent figures. Some of these operations may be deleted or removedwhere appropriate, or these operations may be modified or changedconsiderably without departing from the scope of the present disclosure.In addition, the timing of these operations may be altered considerably.The preceding operational flows have been offered for purposes ofexample and discussion. Substantial flexibility is provided byembodiments described herein in that any suitable arrangements,chronologies, configurations, and timing mechanisms may be providedwithout departing from the teachings of the present disclosure.

Note that all optional features of the apparatus described above mayalso be implemented with respect to the method or process describedherein and specifics in the examples may be used anywhere in one or moreembodiments.

Numerous other changes, substitutions, variations, alterations, andmodifications may be ascertained to one skilled in the art and it isintended that the present disclosure encompass all such changes,substitutions, variations, alterations, and modifications as fallingwithin the scope of the appended claims.

The invention claimed is:
 1. A radio frequency (RF) transceiver device,the device comprising: a first transceiver, to receive a first transmit(TX) signal, where the first TX signal is a TX signal to which a firstmodification has been applied, and where the first modification includesa modification of one or more of a phase and an amplitude of the TXsignal to reflect beamforming along a first plane of a pair of ahorizontal plane and a vertical plane of a beam, wherein the firsttransceiver is to apply a first transceiver modification to the first TXsignal by modifying one or more of a phase and an amplitude of the firstTX signal to reflect beamforming along a second plane of the pair. 2.The device according to claim 1, further comprising a secondtransceiver, to receive a second TX signal, where the second TX signalis a TX signal to which a second modification has been applied, wherein:the second modification includes a modification of one or more of thephase and the amplitude of the TX signal to reflect beamforming alongthe first plane of the pair, the second modification is different fromthe first modification, and the second transceiver is to apply a secondtransceiver modification to the second TX signal by modifying one ormore of a phase and an amplitude of the second TX signal to reflectbeamforming along the second plane of the pair.
 3. The device accordingto claim 2, wherein the second transceiver is one of a second pluralityof transceivers of a second transceiver cell of the apparatus, whereeach transceiver of the second plurality of transceivers is to apply arespective second transceiver modification to the second TX signal bymodifying one or more of the phase and the amplitude of the second TXsignal to reflect beamforming along the second plane of the pair.
 4. Thedevice according to claim 3, wherein each transceiver of the secondplurality of transceivers is coupled to a respective antenna element. 5.The device according to claim 1, wherein the first transceiver is one ofa first plurality of transceivers of a first transceiver cell of theapparatus, where each transceiver of the first plurality of transceiversis to apply a respective first transceiver modification to the first TXsignal by modifying one or more of the phase and the amplitude of thefirst TX signal to reflect beamforming along the second plane of thepair.
 6. The device according to claim 5, wherein each transceiver ofthe first plurality of transceivers is coupled to a respective antennaelement.
 7. The device according to claim 1, wherein: the TX signalincludes a first carrier component in a first frequency band and asecond carrier component in a second frequency band, the secondfrequency band being different from the first frequency band, and thefirst transceiver modification applied by the first transceiver to thefirst TX signal includes different modifications applied to the firstand second carrier components of the first TX signal.
 8. A beamformingdevice for a cellular radio frequency (RF) antenna apparatus, the devicecomprising: a first adjuster, to receive a first adjuster input signalindicative of a transmit (TX) signal in a first frequency band, and togenerate a first adjuster output signal by modifying one or more of aphase and an amplitude of the first adjuster input signal; a secondadjuster, to receive a second adjuster input signal indicative of a TXsignal in a second frequency band, and to generate a second adjusteroutput signal by modifying one or more of a phase and an amplitude ofthe second adjuster input signal; a third adjuster, to receive the firstadjuster input signal, and to generate a third adjuster output signal bymodifying one or more of the phase and the amplitude of the firstadjuster input signal, where the third adjuster output signal isdifferent from the first adjuster output signal; a fourth adjuster, toreceive the second adjuster input signal, and to generate a fourthadjuster output signal by modifying one or more of the phase and theamplitude of the second adjuster input signal, where the fourth adjusteroutput signal is different from the second adjuster output signal; afirst combiner, to combine a signal indicative of the first adjusteroutput and a signal indicative of the second adjuster output into afirst composite TX signal; and a second combiner, to combine a signalindicative of the third adjuster output and a signal indicative of thefourth adjuster output into a second composite TX signal.
 9. The deviceaccording to claim 8, wherein each of the first adjuster input signal,the first adjuster output signal, the second adjuster input signal, andthe second adjuster output signal is a digital signal.
 10. The deviceaccording to claim 8, further comprising a de-serializer, comprising atleast an input port and a first and a second output ports, to thede-serializer to: receive, at the input port of the de-serializer, acomposite input signal, the composite input signal comprising one ormore signal components indicative of the first adjuster input signal andfurther comprising one or more signal components indicative of thesecond adjuster input signal, output, at the first output port of thede-serializer, a signal indicative of the first adjuster input signal,and output, at the second output port of the de-serializer, a signalindicative of the second adjuster input signal.
 11. The device accordingto claim 8, wherein each of the third adjuster output signal and thefourth adjuster output signal is a digital signal.
 12. The deviceaccording to claim 8, wherein: a phase and an amplitude of the firstadjuster output signal are indicative of beamforming for the TX signalin the first frequency band to be transmitted by a first antennaelement, a phase and an amplitude of the second adjuster output signalare indicative of beamforming for the TX signal in the second frequencyband to be transmitted by the first antenna element, a phase and anamplitude of the third adjuster output signal are indicative ofbeamforming for the TX signal in the first frequency band to betransmitted by a second antenna element, and a phase and an amplitude ofthe fourth adjuster output signal are indicative of beamforming for theTX signal in the second frequency band to be transmitted by the secondantenna element.
 13. The device according to claim 12, wherein each ofthe beamforming for the TX signal in the first frequency band to betransmitted by the first antenna element, the beamforming for the TXsignal in the second frequency band to be transmitted by the firstantenna element, the beamforming for the TX signal in the firstfrequency band to be transmitted by the second antenna element, and thebeamforming for the TX signal in the second frequency band to betransmitted by the second antenna element is beamforming along a firstplane of a pair of a horizontal plane and a vertical plane for the TXsignal.
 14. The device according to claim 8, further comprising: a firstdigital upconverter (DUC), to perform digital upconversion to covert thefirst adjuster output to a first upconverted adjuster output; and asecond DUC, different from the first DUC, to perform digitalupconversion to covert the second adjuster output to a secondupconverted adjuster output, wherein the first combiner is to combine asignal indicative of the first upconverted adjuster output and a signalindicative of the second upconverted adjuster output into the firstcomposite TX signal.
 15. The device according to claim 14, wherein thefirst composite TX signal is an intermediate frequency (IF) digitalsignal.
 16. The device according to claim 8, wherein each of the firstadjuster input signal, the first adjuster output signal, the secondadjuster input signal, and the second adjuster output signal is abaseband signal.
 17. A method of operating a beamforming device for acellular radio frequency (RF) antenna apparatus, the method comprising:generating a first adjuster output signal by modifying one or more of aphase and an amplitude of a first adjuster input signal, where the firstadjusted input signal is indicative of a transmit (TX) signal in a firstfrequency band; generating a second adjuster output signal by modifyingone or more of a phase and an amplitude of a second adjuster inputsignal, where the second adjuster input signal is indicative of a TXsignal in a second frequency band; performing digital upconversion tocovert the first adjuster output to a first upconverted adjuster output;performing digital upconversion to covert the second adjuster output toa second upconverted adjuster output; and combining a signal indicativeof the first adjuster output and a signal indicative of the secondadjuster output into a composite TX signal, where an RF signal based onthe composite TX signal is to be wirelessly transmitted by an antennaelement.
 18. The method according to claim 17, further comprising: usingone or more antenna elements of the RF antenna apparatus to wirelesslytransmit the RF signal based on the composite TX signal.
 19. The methodaccording to claim 17, wherein combining the signal indicative of thefirst adjuster output and the signal indicative of the second adjusteroutput includes combining a signal indicative of the first upconvertedadjuster output and a signal indicative of the second upconvertedadjuster output.